Keys and key-seats for shafting.



PATENTED JULY 7, 190a.

, c. HAMMEN.

. KEYS AND KEY SEATS FOR SHAFTING. PPPPPPPPPPPPP LED DBO. 22222 1.

* iii for.

W I I To atZZwhom it may, concern.-

v 50 the other-hand, if the lateral surfaces bind 1 first'the wedgingefie'ct of the other surfaces, j

I ITED STATES TE T] OFFIC CHARLES M N, oF-cHIcAeo,ILLINois.

KEYS AND KEY-SEATS FOR SH'AFTING.

1 SPECIFICATION formingpart of Letters Patent No. 732,738, dated July'7, 1903.

Application filed December 2,1901. Serial No. 84,294. (No model.) Q

l 3e it known that 1, CHARLES HAMMEN, a citizen of the United States,and a resident of Chicago, in the county of (look and State 5ofIllinois, have invented certain new and useful Improvements in Keysand Key-Seats for 'Shafting, of which the following is a specifi cation,reference being bad to the accompa- I Dying i gs, forming a partthereof.

k andkey-seats, as particularly described in the claims.

In the drawings, Figure 1 is a transverse section of a shaft, showing ahub of a wheel keyed thereto according to my invention.

Fig. 2 is a similar view of a slightly-modified construction. Fig. 3 isa section at the line 3 3 on Fig. 2. Fig-4 is a view similar to Fig. 1,showing a modification. Fig. 5 is a section at the line 5 5' on Fig. 4.Fig. 6 is a perspective view of thepreferred form of relief-key.

The customary construction of keys and key-seats,consisting of facingchannels in the shaft and hub adapted to receive a key which isrectangular in cross section and has a slight taper in its dimensionradial to the shaft, thechannels having corresponding taper, the key andchannels, however, having their other sides parallel to the said radialdiinension or with slight taper, is 0 on to certain well-understoodobjections.

If the surfaces tending to exert a wedging force radial with respect tothe shaft come into binding contact and before like contact is obtainedat the lateral surfaces, there is liable to be an initial possibility ofplay under thestress of reversed rotation, and the blow, however slight,which the key and seat receive in such movement tends to crush the metaland rapidly increases the play, which reversion of the direction ofrotation.

the purpose of which is to force the shaft into such contac'twith theopposite sides of the,

bearing that the friction of such engagement shall constitute in'largepart the means of holding the parts againstsli'pping, is defeated.

, The leading feature of my improvement;

consists in such form and location of the keyseats and keys t-hat'eachkey shall be required to produce-binding action only in one plane-thatis, only one pair of its faces having this duty, the other two faceshaving no such duty, and v the key not requiring to be closely fitted inits seat in respect to the said other two faces, and being so fitted,iffat all,

only for the purpose of checking its expansion in that direction underthe stress of the wedging pressure in the other direction.

In the drawings, A represents the shaft; B, the hub of a wheel securedthereto. primary form of my invention (shown in Fig. 1) I employ twokeys 0 O, the seats of each" key in the shaft and hub,respectively,beingv angular and togetherforming a quadrilateral I are to beconsidered are formed one of them entirely in the shaft and theoppositeone entirely in the hub, so that the keyhaving a ta-' per in onedimension andwithout taper in the 1 other dimension being forced intothis cavity tends to crowd apart the faces opposed in the direction ofitstaperingd-imension, tending thus to rotate or roll the shaft slightlyin its- Such action is not contemplated v and is prevented by thelocation of the other key at the opposite side, and preferablysymbearing.

metrically disposed at the opposite side of a diametrical plane parallelto the tapering dimension of the key, so that by driving the two keyssimultaneously the shaftis forced firmly into its seat in the hub,producing the most perfect frictional contact possible through-. out theentire half of'its circumference opposite the chord containing the twokey-seats? As compared. with the usual structure of key lodged in achannel it will be seen that with .substantially equal reduction of thecross-area Patented July 7, 1903,

In the Of the cavities of the shaft by reasonof the cutting out of I thekey-seats there is obtained double facility t for tightening, and at thesame time the primary advantage of my invention is obtained namelygthateach keydoes d u tyin the direction of one dimension only and maytherefore be driven home to the maximum degree of tightnessiuthatdimension not impeded by 'friction upontho other two seats, whichneed not even touch the walls of the recesses and,

; atmost, will be made only an easy fit, since no serviceexceptinclosing the key is required of these'opposite walls of thechamber.

In many situations in'which great security 15 of connection is requiredbetween shaft and wheel thereon -as, for example, in securing RPFOPGllGI WhEGI to its shaft-it is practically impossible to remove awheel when once keyed rupture the hub.

sec'urely'under the old construction, and the only resort in caseremoval is necessary is to With my improved key i and seat it is"practicable to provide a comparatively easy means of withdrawing the fkeys, so as to permit the removal of the wheel. I 5

In. Figs. 2 and 3 I have shown a form in which this can bedone. In thisform instead of one ofthe-keys O, I provide a relief-key D, whose ever,being'preferablyvery much greaterthan would be desirable for a key tobetightened intlie ordinary mannerthat is, instead of r I 35 having thetaper aboutone-eighth of an inch amount, the key-seats beingcorrespondingly tapered. This key hasahead D at the outer taper is inthe opposite direction from that of the key 0, such key D being lodgedin the angularkey-seat-s of the shaft and hub in the same manner as thekey 0, the taper, howto. the foot, asis customary, the key D may have ataper of three or four times that end, which is stopped so that itcannot move longitudinally in the direction tending to slack it. Suchkey D being lodged in posi- 1 tion and the wheel passed onto the shaftbeforethe key 0 is inserted or at least before it is tightened, so as toimpede the application ofthe wheel to the shaft, the subsequent Itightening of said key 0 causes the relief-key upon the one key which isdriven is more se- -vere it may be made of greater area than 5.5 whenboth keys are to be driven, as in the D to be bound tightly between itsseats, all

the duty of tightening, however, devolving upon the key' 0, but withapproximately the same ultimate eifect as if both keys were driven,although in this case since the duty original form. When it is desiredto withdraw the keys and remove the wheel from the shaft, the head D ofthe key Dean be cut j off, and that key can then be driven inward,

which is feasible in view of the taper of this keybeing much greaterthan if it had been designed to be originally tightened by driving. Therelief afforded by driving in this key will-of course relieve thekey O,which. In case of large shafts it may be found desirable to employ a ican then be withdrawn.

third key, the added key beingin all respects 'fore striking thebearing.

like the keys 0, but-for distinction denoted c on Fig. 2. Thisadditional key will be preferably located about opposite thekey C andwill be seatedso as to crowd tangentially in the samecircumferentialdirection as the key ing the transmission of the pressureperfectly from the key Oarouud tokey D. When the wheel to be thus keyedonto the shaft is located near the hearing, so that thekey D can bedriven only a short distance, it will be necessary to cut it away inpieces as it is driven through, and to facilitate this such key may bemade, as shown'in Fig. 3, cut partly in two distance which the key canbe driven in befirst driven in this distance will be cut off at thefirst slit and the piece cut off, and so on until the necessary reliefis obtained.

It is practicable to combine a relief-key,

such as the key -D, with two opposed keys,

both of which are to be drivenasinthe first 'too' constructiondescribed. Such combination is illustrated inFigs. 4t and 5 andconsistsin The key being I the employmentin connection with one of theV.

keys 0 of a false-key seat or relief-key E,

which has the form of the relief-key Dthat is, tapering in the oppositedirection from the keys G and lodged in the seat oras alining of. theseat of one of the keys 0, the taper of' the cavity remaining for thekey when such lining is in place being in the oppositedirection from thetaper of the lining-that is, in the same direction as for the keys 0 Oand at the same pitch. The relief-key or false-key seat E will beoperated in the 'same manner as therelief-key D, that is its head Ebeing cut off, and it may be driven; and it may be driven through torelieve the keys 0 G. In practice, probably, the key 0, which is lodgeda in the relief-key or false-key seat IE, will bedriven in with saidfaIse-keyseat or-relief-i key, the net taper of theltwo parts combinedbeing sufficiently great to permit such action. "1]

In this specification'and claims .I use the phrase the plane of taper toindicate the plane in which the dimension of the key bee. i I

in g m'easured'shows such dimension diminishing steadily from'one endtothe other'and the corresponding phrase taperingin' a transversedimension to indicate the diminu- I tion of the transverse dimension asmeasured in'the plane division by. the description immediately followingthe said phrase.

In fl ing the'key-seatsin the shaftffi facing toward one sidev or theother of t p A v: sha'ft in the specification and claims Ij t J 9. byslits (1 cl at intervals not greater than the to-be understoodasindicating the seat inthe shaft on which the key operates with bindingor wedging effect and todistinguish that seat from the near lateral wallof the key-cham- 5 her .which may be formedby the other side of theangular out which is made in the shaft to produce the key-seat, sincethe key does not bind against said lateral wall or operate upon it inany manner with'tightening effect. I claim- 1. A shaft and hub havingeach two recesses for key-seats, which, when registered respectivel y,form rectangular key-chambers, taper ing in a transverse dimension whichis approximately tangential to the circumference of the shaft;correspondingly-tapered keys in I said chambers, the shaft having itstwo key-- seats on which the tapering, keys act wedgewise, locatedfacing toward the same side of fichambers being in opposite directions,and correspondingly-tapered keys in said cham- 30,, cesses forkey-seats, forming, when registered bers respectively.

. 3. A shaft and hub having eacha pair of refacing each other,rectangular key-chambers tapering in a transverse dimension which is Iapproximatelytangential to the circumference of the shaft, and havingtheir respective 'key-seats in the shaft facing toward opposite sides ofthe latter, said shaft and hub having I a third pair of recessessimilarly registering to form a key-chamber, such third key-chamherbeing tapering in one dimension approximately tangential to'thecircumference of I. thejshaft, itssaid taper being in the opposite.

direction from that of the other two key-chambers. v

4. .A shaft and hub having each two recesses for key-seats, which, whenregistered respectively, form rectangular key-chambers which taper inopposite directions, each in a dimension approximately tangential to thecircumference of the shaft, their; respective key-seats in the shaftfacing toward --the same side of the shaft; corrcspondingly-taperingkeys fitting in said chambers respectively, one of the keys havingtransverse slits at intervals in its length, extending in from theface'which is seated on the shaft. I

5; A shaft and hub having each two recesses for key-seats, which, whgmregistered respec-' tively, form rectangular key-chambers taper-'- ingina dimension which is, approximately tangential to the circumferenceof'the shaft; tapering keys fitting said seats respectively,

one of said keys having a head at its smaller end to stop it againstlongitudinal withdrawal, such head being exposed so that it can i be cutoff to permit the key to be forced out;

' 6. A shaft and hub,each having two recesses forkey-seats, which, whenregistered respec: tively, form rectangular key-chambers tapering'in atransverse direction, which is approximately tangential to thecircumference of the shaft; tapering keys in said seats re- 7spectively, one of said keys having at itssmaller end'atransversely-projecting head,

the shaft having a recess beyond the face of the hub to receive saidkey-head.

In. testimony whereof I have hereunto set" my hand, in the presenceoftwo witnesses, at Chicago, Illinois, this 21st day of Novem-;

her, A. D. 1901. v v q I -GHASLIIAMMEN. In presence of-- v l 1 OHAs. S.BURTON,

HAROLDWARNER.

